#include "il2cpp-config.h"

#if IL2CPP_TARGET_POSIX

#include "os/Cryptography.h"
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>

#ifndef NAME_DEV_URANDOM
#define NAME_DEV_URANDOM "/dev/urandom"
#endif

static int64_t file = -1;

namespace il2cpp
{
namespace os
{

void* Cryptography::GetCryptographyProvider()
{
	return (file < 0) ? NULL : (void*)file;
}

bool Cryptography::OpenCryptographyProvider()
{
#ifdef NAME_DEV_URANDOM
	file = open (NAME_DEV_URANDOM, O_RDONLY);
#endif

#ifdef NAME_DEV_RANDOM
	if (file < 0)
		file = open (NAME_DEV_RANDOM, O_RDONLY);
#endif
  return true;
}

void Cryptography::ReleaseCryptographyProvider(void* provider)
{
}

bool Cryptography::FillBufferWithRandomBytes(void* provider, uint32_t length, unsigned char* data)
{
  int count = 0;
  ssize_t err;

  // Make sure the provider is correct, or we may end up reading from the wrong file.
  // If provider happens to be 0 we will read from stdin and hang!
  if ((int64_t)provider != file)
    return false;

  do
  {
    err = read ((int)(size_t)provider, data + count, length - count);
    if (err < 0)
    {
      if (errno == EINTR)
        continue;
      break;
    }
    count += err;
  } while (count < length);

  return err >= 0;
}

}
}

#endif
